putting coal miners back to work, that is a promise president trump made during his 20 16 campaign. that's proving harder and harder to keep. after the largest private coal miner in the u.s. filed for bankruptcy last week, it appears that the coal industry is in deep trouble which could also spell trouble for trump in 2020. cnn's tom foreman reports. >> reporter: through the whole crumbling kingdom of coal the bankruptcy of murray energy is sending shock waves as the largest private coal mining operation in america murray long painted a rosie picture of the industry. >> this is high quality coal produced through the efforts of nearly 7,000 people. >> reporter: even as president trump promised to help struggling coal communities everywhere. >> we are going to put our coal miners back to work. >> reporter: to be sure, the